Catheters which are used to remove occlusive material from lumens within the body are well known. They range from simple aspiration devices to complex high energy devices
Occlusive materials such as plaque, atheroma, and emboli vary in their mechanical properties and various energy sources have been proposed to break up occlusive material. These proposals include the use of high energy fluid jets or the circulation of abrasive slurry within the vessel. The use of mechanical impellers and/or blades has been proposed and clinical work has been performed with a “rotorblader” device.
Laser light energy and either ultrasonic or acoustic energy have been proposed to breakdown occlusive material. The use of radio frequency electromagnetic energy has been proposed as well.
For example fluid pressure thrombectomy systems are known from U.S. Pat. No. 4,690,672 to Veltrup among others. In the Veltrup device, a reward-facing jet entrains thrombus and blood from the patient, and ejects these into a secondary discharge lumen, which removes both thrombus and blood from the body.
Impeller based cutting devices are known from U.S. Pat. No. 4,729,763 among others. In this device the mechanically rotated blade interacts directly with the occlusive material.
Ultrasonic based devices are known from U.S. Pat. No. 5,368,557. In this device the ultrasonic energy is used to break up the occlusive material and a fluid is supplied to cool the ultrasonic tip.